Partition coefficients of 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) in erythrocyte lipids in multiple sclerosis

Abstract
Electron spin resonance (ESR) was used in a search for a possible generalized membrane defect underlying myelin instability in multiple sclerosis (MS). In contrast to most ESR studies of biological membranes, a small, nonelectrolyte spin label, TEMPO, was chosen; its partition coefficient was determined in extracted erythrocyte lipids from MS patients and normal controls. No differences were observed. The advantages and limitations of TEMPO in comparison with lipid spin labels as probes for the study of biological membranes are discussed.